Master sheet clamping means for duplicating machines



March 28, 1950 H ROBENSON 2,502,278

MASTER SHEET CLAMPING MEANS FOR DUPLICATING MACHINES Filed Jan. 51 1.948 5 Sheets-Sheet 1 IN V EN TOR.

[ LU HEN/2y GPoB/NsaN H. G. ROBINSON MASTER SHEET CLAMPING MEANS FOR DUPLICATING MACHINES March 28, 1950 Filed Jan. 51, 1948 5 Sheets-Sheet 2 A TORNEYS 5 sheets-sheet 5 March 28, 1950 H. G. ROBINSON MASTER SHEET CLAMPING MEANS FOR DUPLICATING MACHINES Filed Jan. 31, 1948 M N NT IV Tmx V Q N am? l R w b II m M QT E 5 v 1 a; w? NV w an \v ,i v II I :25 3 E 55 Y m? 1 N m E j @m mm kw w ow Hm H l w V. l I 1 B W wm ww ww (1Q III M am mm HWI I I w? 4 .F w d v a Mm" v Q1 k 2 W m H m7- 1 \T/S ID i N Nm N n H 4 1 u 1 mm w AT TORNE)6 March 28, 1950 H. G. ROBINSON 2,502,278

MASTER SHEET CLAMPING MEANS FOR DUPLICATING MACHINES Filed Jan. 31, 1948 5 Sheets-Sheet 4 I N VEN TOR.

March 28, 1950 ROBlNSON 2,502,278

MASTER'SHEET CLAMPING MEANS FOR DUPLICATING MACHINES Filed Jan. 31, 1948 5 Sheets-Sheet 5 INVENTOR. HENEY 6. Foal/v.90

Patented Mar. 28, 1950 MASTER SHEET CLAMPING MEANS FOR DUPLICATING MACHINES Henry G. Robinson, Lakewood, Ohio, assignor to The Lamson & Sessions Company, Cleveland, Ohio, a corporation of Ohio Application January 31, 1948, Serial No. 5,590

The present invention relates to duplicating apparatus of the type wherein data on a master sheet, which is secured to a rotatable drum, is transferred either directly or indirectly to a copy sheet; and is an improvement on the invention disclosed and claimed in my copending application Serial No. 592,225, filed May 5, 1945, issued to Patent No. 2,479,865 on August 23, 1949, the present application being a continuation-in-part thereof.

My prior application, referred to above, discloses a duplicating machine of the character mentioned wherein the drum for supporting the master sheet is formed in part by movable portions that can be raised to insert or tuck into the interior of the drum parts of the master sheet which it is desired not to reproduce on the copy sheets. In the embodiment shown in said application the movabl sections of the drum are pivoted about their trailing edges, however, it is un derstood that they could be slidably supported for reciprocation radially of the axis of the drum, if desired, or could be movably mounted in other manners.

In order that a duplicating apparatus of the type mentioned will produce satisfactory copies of the desired data on the master sheet, it is necessary that the movable sections conform to, or lie in, the cylindrical surface of the drum during operation of the machine. Also, the external surface of the drum must be free of projections or recesses throughout the portion thereof upon which the master sheet is secured, which portion comprises substantially the entire length of the drum except for a narrow band at each end of the drum. Because of these requirements, and the fact that the ends of the drum are rendered inaccessible due to the housing of the apparatus, the provision of satisfactory means for lifting the movable sections presents a diflicult problem.

- The principal object of the present invention is the provision in a duplicating machine, of the character referred to, of novel means for raising the movable sections of the drum which means is simple in construction and convenient to operate.

Another object of the invention is the provision in a duplicating machine of the character referred to, of a novel means which is operable from .the exterior of the machine for selectively raising the movable sections of the drum.

A more specific object of the invention is the provision in a duplicating machine of the charac- 1 ter referred to, of novel means including a cam selectively positionable for cooperation with pro- 12 Claims. (Cl. 101-132) jections upon the movable sections of the drum for effecting raising of any or all of the movable sections of the drum.

A further object of the invention is the provision in a duplicating machine of the character referred to, of a means for counteracting the tendency of the movable sections of the drum to open as they pass over the roller which effects the transfer of the data from the master to the copy sheet.

The invention further resides in certain novel features of construction, and combinations and arrangement of parts, and further objects and advantages thereof will be apparent to those skilled in the art to which it pertains from the following description of the present preferred embodiment thereof, described with reference to the accompanying drawings in which similar reference characters represent corresponding parts throughout the several views, and in which:

Fig. 1 is a plan view of a duplicating machine embodying the present invention with parts of the frame or housing broken away to show portions of the operating mechanism of the machine;

Fig. 2 is a fragmentary sectional view, taken approximately on the line 2-2 of Figs. 1 and 3;

Fig. 3 is a fragmentary sectional view taken ap-' proximately on the line 3-3 of Fig. 2;

Fig. 4 is an enlarged sectional view through the master sheet carrying drum, shown in the preceding figures, the section being taken approximately on the line 4-4 of Figs. 3 and 5 with parts broken away to more clearly show the construction;

Fig. 5 is an enlarged elevational view of the left-hand end of the master carrying drum as viewed in Fig. 1 the drum being rotated from its position illustrated in Fig. 1;

Fig. 6 is an enlarged fragmentary view, partly in section and partly in elevation, illustrating the manner in which the movable sections are opened by the mechanism of this invention;

Fig. 7 is a detached front elevational view to an enlarged scale showing the lever on which is mounted the novel mechanism for preventing the movable sections of the drum from opening during operation of the machine;

Fig. 8 is a side elevational view of the parts shown in Fig. '7, as seen from the right of Fig. 7; and,

Fig. 9 is a fragmentary sectional view taken substantially on the section indicating line of Fig. 7.

The invention is herein illustrated and described as embodied in a duplicating machine those parts which are necessary to a complete understanding of the present invention are herein illustrated and described in detail;

Referring to the drawings, the dupli'catingmachine shown therein comprises frame, "designated generally by the referenceacharacter-Aand including two sheet metal side members it, :H

and a feed table I2, .At the dischargaendofthe table I2, and disposed between the side members Hi, I I, is a master carrying drum B fixedstoiashaft l3 journaled in the side frame members I 8, I i by anti-friction.bearingsl i, 15, see Fig. 3. The drum 3 is adapted tohave a master sheet or sheets secured thereto in a manner hereinafter specifically described.

The copyisheets are fed to the. drum B by a rubber roller. Iiifixed to a shaft- !8, see Fig. 2, opposite. endsof whichv shaft are journaled in the ends of .le vers.=20, one at either side of the machine, which levers. are, in turn, journaled intermediate their ends upon a shaft 2| extending between the side frame membersnlfl, ll. Theopposite ends-of the levers are provided-with a pluralit of notches-22 adapted to .havethe upper ends of springs 23 engage therein. Theilower ends of the springs '23 are connected by..pins, not shown, to the. sideframe members ID, .I I. The springs 23 yieldabl urge the roller l1. against. a composition roller 24, located directly above the roller 1 I, and, the pressure with vvhichthe roller 1'! engages the rolleriil can .be adjustedbymoving the up- .perendsof the springs .23 fromone to another of thenotches 22.

Theroller. His on. a shaft .25, opposite. ends of which arejournaled, in amannernot shown, in

members carried by the side frame members ill,

l|.. Extending across the upper surface of the roller. 2415 a plate Elishapeclto conform to the circumference of :the'roller and which prevents .the .copy sheets. from vbeingdrawn around: the roller. during operationeof the machine. right-hand. end of the shaft 25, as the machineis viewed. in Fig. l, is provided witha gear, not shown, fixedlysecured thereto, which-gear is continuously in mesh With a gear 21. The gear 27, in

turn, mesheswith. a. gear-.28 mounted on oneend of the. shaft .l3. ..The gear. 28 is fixedly secured by pins. 31 :to theright-hand end member 3a of the drum B, which pinsalso project through a geartZ continuously in mesh. with a pinion 33 fixedto .a shafttt, see Fig. 3. The shaft 34 is rotatably supported by a suitablebearin 3.5 .in the side frame member H and' projects through the side frame member, the outertend of the shaft beingprovlded with acrank- 36. Hence, when the operator turns the crank.36,.theshaft 34 and the pinion .33 are rotated-thus causing: gears' 32, 28 and drum B to rotate; -Rotation of gear 28 in turn causes rotation of gearq2i'i and roller: 24 and, since-the rollersv [-1 and; 24 are. in frictional engagement, the roller I! rotates in unison with the roller, 24..

Asthe copy sheets arezfed to the drumB bythe rollers l? and 24, they are pressed against the mastersheet or sheets carried by the drum B by a rubberrollerS-l mounted onza'shaft'tfi journaled The in bell crank levers 4i] and 4|! one at either side of the machine. The levers 4c and 49 are pivotally connected to the side frame members H), II through the medium of pins 4| and 4| connected to the levers intermediate their ends and rotatably supported in members 42 secured to the side frame. members. The' en'ds of the levers 4D and 49 opposite .to theiends which support the roller 37, project in a downward direction and are each provided with an apertured boss to receivescrews43 adjustably secured thereto by jam nuts '44, see F.gs;7 and 8. The heads of the setscrews 43 abut cams G5 fixed to a shaft 4-6 which is ,iournaled in .the side frame members it, II.

"The shaft .464s provided at its right-hand end,

as-viewed in Fig l, with a knurled knob t? so that theshaft ma be. rotated to adjust the pressure with which the roller 3'! presses the copy sheets against the master sheet or sheets on the drum B. A detachable tray 48 is provided at the opposite-side: 0f the drum B fromat-he :feed table l2 for receiving the copy sheets after they-have passedbetween-the master drum B and the roller 31.,

As: the copy sheets are fed through the machine, each copy sheet is moistenedon the side whichcomes in contact with the master sheet or sheets on the drum B .by-the composition roller 24' which is supplied With a solvent for the ink, or the like, on the master sheet by mechanism designatedgeneraliy by thereference character C. This mechanism C comprises a felt strip 50 continuouslyurged into engagement with the comthat a selected portion or portions of one or a plurality of master sheetssupported n thedrum may be-duplicated or reproducedon a single copy sheet; during onepass through the-'machine. To this end the cylindrical'wall' or surface 52 of the drum B has a plurality of apertures therein adapted to receive. a portion or portions of a master sheet or sheets. -.As -shown,-athe cylindrical wall--52 comprises'a pluralityof movable segments hinged at one end to the drumproper. In..-the particular embodiment illustrated, five segments D, Di, D2, D3 and D4 are'e-mployed; but it is to Ice-understood that more or less segments may lee-provided, as required. Each of the segmentsD to D4: aresalike andrhence a descriptionof one is a description of all.

In addition to the construction previously described, the drum- B includes meansfor clamp ingbne -end of a mastersheet to the'cylindrical wall or surface 52 of the drum. Thismeans comprises a plurality of clamping members 53 which are supported in spaced relationship on a shaft54, the shaft being journaled-in members 55 which: are. fixed to the'right-handimember 30, previously referred to, and to the left ha'nd end member 56 of the drum B. The outer'ends of the clamping members 53 projectthrough spaced, axially aligned openings in the: cylindrical wall of--drum B, which openings are circumferentially spaced in a counterclockwise direction from the segment: 4D, see. EigsLI Z and 4. Theseopenings each merge with a V-shaped recess or groove 51, extending axially of the drum adjacent the outer ends of the clamping members and the lower surface of each of the members,

adjacent its outer end, is sloped to cooperate with the adjacent sloping surface 58 of the groove 51. The members 53 are supported on the shaft 54 for limited angular movement thereabout and are continuously urged in a clockwise direction, as viewed in Fig. 4, by springs 88 which are operatively connected to the members 53 and to pins 6|, the latter being fixed in the shaft 54 and extending outwardly through suitable slots in the hubs of the members 53.

The construction just described is such that upon rotation of the shaft 54 in a counterclockwise direction, as viewed in Figs, 2 and 4, the members 53, after the elapse of a short lostmotion movement, are moved with the shaft as a unit to disengage their free ends from the inclined surface 58 of the groove 51 so that the end of a master sheet may be inserted therebetween. When the shaft 54 is rotated in the opposite direction, the clamping members 53 are permitted to move in a direction toward the inclined surface 58 and are ultimately individually urged thereagainst by their respective springs 88 thereby clamping the end of the master sheet to the drum. In the particular embodiment shown, six clamp members 53 are employed, however, it is to be understood that any desired number may be used.

The right-hand end of the shaft 54 is provided with a lever 52 fixed intermediate its ends to the shaft 54. The right-hand end of the lever 52, as viewed in Fig. 2, carries a pin 63 to which the upper end of a tension spring 64 is connected so that the shaft 54 is continuously urged in a clockwise direction, as viewed in Fig. 2, which is the direction of movement for causing the clamping members 53 to engage with the end of the master sheet E. The lower end of the spring 64 is connected to a pin 55 projecting from a lug 65a formed integral with the drum B. The end of the lever 52, opposite to the end connected to the spring 64, is adapted to be selectively engaged by the free end of the lever 66 pivotally connected to the end frame member H by a pin 61. The lever 66 is adapted to be rotated about its pivot 61 by a hand lever 68 which is pivotally connected to the end frame member H by a pin 10. The lever 58 is provided with a pin 12 which continuously engages within a slot 13 in the lever 65.

When the parts are in the position shown in full lines in Fig. 2, the drum B is free to rotate and the clamping members 53 are in their engaging position. When it is desired to move the clamping members to their disengaged position, the lever 86 is moved into engagement with the lever 52 by rotating the hand lever 68 in a clockwise direction. Continued movement of the hand lever, after the lever 56 has engaged the lever 62, moves the latter and thus rocks the clamping members 53 into the position shown in dot-dash lines in Fig. 2, which is their disengaged position. Initial movement of the lever 86 also engages a roller 14, carried by the lever 66, within a slot 15 in the end of the drum B, thus locking the latter against rotation. v

A cam 16, having a concentric dwell'lGa, a lobe 16b and a depression 11, is secured to the outer face of the end member 56 of the drum B, see Figs. 2 and 3. This cam is continuously en'- gaged by a roller 18 connected to therear'end of allever 88 which is pivoted intermediate its ends on a stub shaft 8! projecting from the side frame member Hi. The front end of the lever 88 is operatively connected to a lever, 82 also piv-F otally supported on the shaft 8|, which lever is actuated upon actuation of the lever 88 by the cam 76 to supply solvent, in the manner disclosed in the aforementioned U. S. Patent No. 2,145,729, to the chamber 5| of the moistening apparatus C. The roller 18 is continuously urged toward the cam 18 by a compression spring 83 interposed between the lever 88 and a bracket 84 fixed to the inside of the frame A.

The members or segments D to D4 may be movably connected to the drum proper in any suitable manner. As shown, each segment is supported for pivotal movement about an axis parallel to the axis of the drum and located adjacent to the trailing side of the segment, referring to the direction of rotation of the drum during operation, which direction is indicated by the arrow R in the various figures. This pivotal mounting of the segments D to D4 to the drum proper is effected by screws 85, the reduced inner ends 85 of which project into suitable holes in the ends of the segments. The screws 85 also project through holes in members 81, one of these members being positioned adjacent each end of each segment in a slot in the inner face of the latter so that the screws 85 connect the said members to the segments. Each of the members 8'! has a portion thereof projecting radially inwardly of the drum, see Fig. 41, where they are engaged by springs 88 located .in annular grooves 98, 8| in disks 92, 93, re-

spectively. The disks 92 and 93 are fixed to the inner faces of the end members 38, 55, respectively, of the drum as by screws 94. The springs 88 are more or less U-shaped and are held in position in the grooves 98, 8| by screws 95, the

:parts of the springs which are not engaged by the members 87 abutting the bottom of the grooves. The construction is such that the inwardly extending parts of the members 81 act as cams and cooperate with the springs 88 t0 resiliently hold the segments D to D4 in either open or closed position as shown in Fig. 4, pins such as 96 being provided to limit the outward movement of the springs 88 when the segments are in open position.

In order to selectively move the segments D, DI, D2, D3 and D4 to open position, the segments, in accordance with this invention, are each provided with members or pins 91 connected to the sides of the segments adjacent those edges thereof which are the leading edges when the drum is rotated. The members or pins 9 1 are fixed within suitable apertures in the segments and project axially of the drum into apertures or recesses 98 in the surface of the drum adjacent to the segments. The engagement of the members 8! with the bottoms of the recesses 98 limits the movement of the segments towards the center of the drum so that the outer surfaces of the segments, in their closed positions, are substantially coextensive with the surface of the drum. The free end of each of the members or pins 91 is offset radially and axially of the drum to provide an axially extending portion 91' spaced slightly above the surface of the drum. These portions 91' constitute means by which the segments may be raised to open position as hereinafter described.

A stationary cam member 99 is reciprocatingly "7 amounted impair :the upper t portion :of the iframe member lil f for movement :axially withrespect .to':the;drum Bifor the purpose ofJSeleQtiVeIy -engaging ithe 'portions 9?. ef :pins :91 and thereby ifie'ct movement of :the corresponding segment on segments to open .positiom when :thecdrumis rotated; As seen:.in.Figs..-2, 3 and 6, the .cam member-99 has an inclined:icammingtsurface I110, extending angularly with frespectfto :the surface of the drunn and an :arcuately curvedzbottom surface adapted L to project rover the edge Off'thE surface of I the drum, in relatively: closely spaced relationship thereto, when the cam memberis in its forward position. ihe construction is such "thatwhen the cam' iiii is projected forwardly, as

hereinafter described, it is disposed in the path of -the portions fil' of the pins 9'! which are *afiixed to the movable segments D'to D5. Hence, when 'thedrum is -mtated inthe direction indicated by thearrow the portions '9'! of pins '9'!- successively engage the cam 99 and ride up the inclined surface Hit thereofthereby moving the correspondin movable segment of the drum to open position. The height of the cam 99is such that the segment or segments are moved to fully open positionby the time that the portion 91" of :its-pin filmoves over the top of the cam, the::segment being'retained in open position as previously described by'th'e action of the spring "88 bearing upon the member 81.

The cam: 89 is reciprocably'mounted for movement into 'and'out of the path of the portions 191' of'pins 3? :by means ofspaoed dowel pins l-lll and H32 which are secured :to the cam 99 and areislidably received'inbores intend I04 'of a mounting member or boss 5 ilfisecured to the side m'ember ID of frame A. As shown in the drawings,'thisboss ormounting member I05 is shown as secured to the side :member It by screws or other suitable means me although. it

will beunderstoodthat the: member I05 may be :formed integrally with the side member .IB ."lf

desired.

The mounting member: 1&5 is provided with a bore l'fi'Lwhich isco-unterbcred as indicated at 108, and the'side member iii/is provided with an opening communicating with the countervborel'iitibut of smaller diameter than thexsaid counterbore.

member "lil'a-ndflthec'boresi iii? and H38 of'member 105, the inner-end oftherod $69 being secured to the cam membertii. :Disposed within the counterbore. I88, and surrounding the rod [$9,13 zazcompression'spring Hi} which cooperates with the bottom of the :coun'terbore 188 and withia collar lll upon rod we to normally retainthe :cam member 99 in its retracted .position'as shown in-Figs. l and 3. 'The outer end cf rod HES-is provided with a'knob or handle I l2 by which the'rod 299 may be moved towards the drum against the action of spring H0 thereby dis- .movablesegmenttor segments of the drum may be readilymoved to open position'for the pur- An actuating member, "illustrated as a rod Hi9, projects througirtheopening inthe use *rposesnf inserting a portion ror "portions :of :the I master. sheets-into :theiinteriorlsof.ithedrumtwhich zinserte'd portions correspond to data on :the .master'sheet' which. it is. not desired to reproduce .upon copy sheets. The segments such :as .D vwhich :have been :moved to 1 open position are lielosecl, .after the .pins -dl thereon ;have :passed cbyathe "cams99 .or:.the latterxhas been retracted, .by'theoperatorsimply pressing uponthe outer surface cit-each open .segment. This. deflects the springs 538 "of the open segment sufiiciently to :allow the membersBl to move, from a position in which ithespring cooperates with the said members to hold the segment open,'to1the posittion in which the spring cooperates .with the -members .81 "to hold-the segment in closed 'posi- :tion.

"The trailing edges of leach of .the movable ==segments D to m are provided with a plurality of projecting plugs or buttons l l3, see Figs. 4 and iiiormedoi: rubber, leather or the like, which engage the leading edge ocfthe next. succeeding csegmentwhen the segments are in closed position. For examplegthe plugs or projections. I 23 onxthe trailing edge of segment I) engage the leadingedgeiof segmentDLetc the plugs or buttons I I3 on segment Di engaging the .ad- Ijacent edge of surface 52 of the drum. That edge :of surface 52=of thedrum which is ad- -jacent the-leading edge of segment D is also provided :with similar plugs or :buttons Hi3. These plugs or buttons serve to firmly grip the wmaster sheet E when a portion thereofis tucked -in' or inserted :within *the drum as 1 indicated .lbythedotted lines .in:F'ig. 2 thus preventing the'insertedtportion from being pulled out of the drum during "the'normal operation of the 'machine.

Theaction of the :springsififl sufficient to cretain thesegments D to D l'in closed positions except for the interval during which thez'trailing edges 'of the 'segments'passover the roller 31. :At this time, =110WV61,'th6 pressure of the roller 31 acts upon the trailing. edges of the segments 'in a:directiontwhichitends to'pivot them out- -wardly with'the result'thatthe segments move slightly" with 'respeotto'the: surface of the drum. This movement-or the segments is undesirable =-=since it'ten'ds'to l00senxor tear themaster sheet supported upon thedrum by exerting force upon the 'portion of the master sheet extending over the segments. 'Inor'der to counteract this action of the roller 53?, andithereby prevent the movable portions of the drum from moving as just mentionedythe arm 49" which supports the *roller 3! is provided with a second roller 14 disposed in aposit-ionto contact the leading edge *of a 'movable'segment, such as D, at the'same lti-methat the-roller :37 is contacting the trail- "ing=edgeof thesegment D. -'As shownin Figs. "2 and "7, this roller 5 i4 is relatively short in *an axial direction and is of smaller diameter *thari the roller sl.

The roller H4 is'journaled upon the outer arm 'of'acrank-like member H5 the other arm H6 "or the crank member-being pivoted to the arm 45 by a suitable'stud 'or the like '4! the'hea'd of'which'is cylindrical to'provide a'pivot for the arm 45] "as-previously described. The arm H6 of the crank I I5 is'provided with a substantially "cylindrical portion, adjacentthe arm '49, to which an ajdjusting'arm I I! is secured by means of'a1pinil8 *or'the like. 'The arm ll'l'has an elongated portion extending parallelwith a corresponding elongated portion ofthe arm 49' and this portion of the arm H1 is provided with an adjusting screw H9 which is threaded through the arm Ill and is provided with a jam nut I20. The end of the screw H9 is adapted to engage a projection 12! upon the arm 40, which projection is illustrated as a separate element connected to the arm 40' by a screw or the like I22 but it will be understood that this projection may be formed integrally with arm 48' if desired.

As was previously described and as shown in the aforementioned Patent 2,145,729, the outer end of the arm 40' is provided with a screw or stud 43 which cooperates with the cam 35 for adjusting its position to thereby adjust the pressure between the roller 3! and the drum B, the arm 40 being pivotable about the head of the stud 4| mounted in the boss 42. When the arm 40' has been adjusted to provide the desired pressure between roller 31 and drum B the arm ll! may then be adjusted relative to the arm 40' by means of screw H9 so that the roller IM exerts sufiicient pressure upon the drum B to counteract the pressure of the roller 31 in its tendency to open segments such as D. The arm N6 of the crank H is preferably provided with i a groove 12-3 to receive the usual notch in the forward portion of the detachable tray 48 as shown in Fig. 2. While only the arms 40' have been shown as provided with a roller H4 it will be apparent that a similar roller may be provided on the similar arm 4!] if so desired.

In operation, a master sheet E, containing the data which is to be either partially or completely reproduced upon the copy sheets, is connected to the drum B by clamping one end thereof between the inclined surface 58 and the clamping members 53. The free part of the master sheet may be merely wrapped around the drum or one or more portions may be enclosed within the drum, for example, a portion or portions not to be reproduced may be so disposed. This insertion of a portion of the master sheet into the drum is accomplished by opening the proper segment or segments D to D4 and tucking the undesired part or parts of the master sheet in I the opening therebetween and the next adjacent segment or adjacent edge of the surface of the drum as the case may be. The opening of a segment or segments D to D4 is readily effected by simply pushing inwardly on the knob H2 and rotating the drum whereupon the cam 99 engages the pin 91 of the segment to be opened, the segment moving to open position as the portion 91 of the pin moves over the surface I00 of the cam. Releasing the knob H2 causes the cam to be retracted from the path of the pins by the action of the spring H0 so that the cam is not left in position to open the segments during the operation of the machine. After the undesired portion of the master sheet has been inserted in the drum, the open segment is closed by the operator pressing thereon, the manner in which a portion of the master sheet is disposed within the drum being illustrated in dotted lines in Fig. 2. This operation may then be repeated for inserting other portions of the master sheet within the drum. After the master sheet has been properly disposed on the drum, as just described, the machine is operated in the corn ventional manner by simply turning the crank 36, the roller H4 counteracting any tendency of the segments D to D4 to move in an opening direction as their trailing edges pass over the roller 31.

While the invention has been described in considerable detail and as applied to a commercially known duplicating machine it is to be understood that the invention is not limited to the particular construction shown or to the particular type of duplicating machine shown but may be otherwise incorporated and embodied in other types of machines. Various modifications and adaptations of the invention will readily suggest themselves to those skilled in the art and therefore the invention is not to be considered as limited to the exact construction herein shown and described but only as required by the spirit and scope of the appended claims.

Having thus described my invention, I claim:

1. In a duplicating machine having a hollow rotatable drumwith a cylindrical surface adapted to carry a master sheet from which copies are to be made, the drum being provided with movable means for clamping said sheet thereto and having a portion of the cylindrical surface movable for insertion of a portion of said master sheet that improvement which comprises a projection on said movable portion of said drum surface extending slightly above the surface of said drum adjacent-an end thereof, and means adapted to be projected over a portion of the surface of said drum adjacent the end thereof and into the path of said projection for engagement therewith as the drum is rotated to effect movement of said movable portion relative to the surface of said drum thereby providing an opening into the interior of the drum for insertion of a portion of the master sheet carried upon the surfaceof said drum. I

.2. The combination as defined in claim 1 and in which the said means is a non-rotatable cam and is provided with means normally maintaining the said cam retracted out of the path of said projection, the combination further comprising means by which the said cam may be moved into the path of said projection against the force of the said means normally-tending to retain the cam in its retracted position.

3. The combination as defined in claim 1 and in which said means for engaging, the said projection is anon-rotatable cam member, the combination further comprising means mounting said cam member for reciprocation into and out of the path of said projection, means for normally holding said cam out of the path of said projection, and means by which said cam may be moved into the path of said projection against the force of the last-mentioned means.

4. A duplicating machine comprising a frame,

. a hollow cylindrical drum rotatably mounted in said frame and adapted to carry a master sheet from which copies are to be made, a portion of the peripheryof said drum being formedby a segment pivoted adjacent an edge. thereof to swing'outwardly relative to the remainder-of the periphery about an axis extending parallel with the axis of the drum, a roller adapted to engage copy sheets with said master sheet on the drum with suiificient force to effect transfer of the data from the master sheet to the copy sheets, and

anaemi ."111 when the .edge adjacent the pivotal axis :is passing over the .first-rmentionedrroller.

6, .A combination as defined in claim .4 ran-d further comprisingimeans.ioriadjusting the force exerted .by the means for counteraotingthe-force of said roller uponsaidsegment.

v"Z. A duplicating machine comprising airame, a ,hollow cylindrical drum rotatabl-y mounted-in saidirrame, clamping means .on said..drum .forsecuring to the drum an edge of a (master sheet from which copiesareto he made, a .portioncf the periphery Eof said drum :being .formed by :a segment pivoted adjacent .an .edge thereof to swing outwardly ,relative to :t'he remainder .of :the periphery of the drum .about an axis extending parallel with the axis of the drum thereby ,pro- .viding an opening into-theinterior of .the .drum for insertion of .a portion of lthemaster sheet, a ,projection on said pivoted segment .extending above the surface ofsaid drumladjacent an end thereof, means carried .by said frame ,and .adapted .to be .moved .into the pathpf ;said projection to engage ,the latter and to swing, .the segment to open positiomraroller cooperating mithsaiddrum for engaging copy sheets with the master sheet upon .the latter with sufiioient force to effect transfer 01 the data of .the .master sheet to the copy .sheetfand means cooperating with said pivoted segment during the .time that the {region thereof .adjacentrits pivotal .axis .is passing .ouer I said roller to prevent the segment .from swingin'g relative .to the surface ;of thedrum about ,its pivotal :a-xis due to the force exerted .by said roller.

8. A'combination asdefinedinrolaim ,7 :and in which thesaid .means adapted to be disposed in the ,path of said projection ,is .a .nonarotatable cam, the combination further comprising .means for ,normally maintaining said roam :out ,of .the path of said projection.

.9. .A combination :as defined in qclaim :and further comprisingmeans for ,adjustingthe pressure exerted by the last-mentioned .means upon said pivoted segment.

.10. .A combination :as defined ,in .claim '7 and face-adapted .torcarry a.master sheet,..means for j clampingan edge of a .master sheet to said surface, the said surface having an aperture therethrough extending substantially axially thereof and adapted .to enable .a portion of the master sheet to .beinserted 'therethroughinto the interior .12 .of the -;drum, asegmentalmember movable with respect to said cylindrical surface and :adapted to substantially .close said aperture in one positicn in which position the said segment cooperates with said cylindrical surface to provide a substantially continuous smooth surface withthe inserted portion 1.01? the master sheet extending ibetweenaa longitudinal edge of said aperture and the adjacent edge .of said segment, andresilient means carriedby one of saidedges and adapted to engage a :part of the inserted portion of said master sheet :to thereby hold "the latter in engagement with said other edge.

12. In a duplicating machine, the combination of -:a hollow rotatable drum having a cylindrical surface adapted to carrya master sheet, means for clamping an :edgeof a masters'heet to said surface, the said surface having an aperture therethrough extending substantially axially thereof and adapted to enable a portion of the master sheet .to be. insertedatherethrough into the interior of the :drum, a segmental member movable with respect to said cylindrical surface and adapted to substantially .close said aperture .in one position in which position the said segment cooperates with said cylindrical surface to provide a substantially continuous smooth surface .with the inserted portion of :the master sheet .-ex-- tending between a longitudinal edgeof said aperture andthaadjacentedgeof :saidsegmentresil- .ient means carried ':.by one of said edges :and adapt-ed to engage ,:agpartof -,the inserted portion of .said master :sheet -;to thereby hold the .latter in i'engagement with said {other "edge and to :resist movement of .zsaidzsiegment irom itsisaid one position, a projection on said :movable segment gextendingeslightlyiabove the outer suriaceof the latter adjacent ant-end of said drum, and means *adaptedetobe projectedjnto the path of said pro- ,jection,foraengagement rtherewithas the drum is rotated and to 'effectmovement; of said segment relativetosaid cylindrical SHI'fECBISO'tha-t a portiono'f said mastensheet maybeg-insertedthrough said aperture or removed therefrom.

HENRY G. ROBINSON.

.RF-EERENCES CITED The following references are 'of record in the file'ofithis patent:

"UNITED STATES PATENTS .Number :Name Date 2,083,044 cStorck June 8, 193'? 2,141,407 Ritzerfeld Dec. 27, 1938 $2,172,876 -Marohev Sept. 12, 1939 2,220,265 3Morrison Nov. .5, 1940 "2374,0239 ERockhill .Apr. 17, 1945 2,380,744 Ford .July 31, 1945 

